1. Field of the Invention
The present invention relates to a spindle motor and more specifically to a disk drive apparatus including a spindle motor.
2. Description of the Related Art
A disk drive apparatus, such as, for example, a hard disk drive, includes a spindle motor arranged to rotate a recording disk. A spindle motor described in JP-A 8-228465 includes a frame and a stator core fixed to the frame. The frame includes an increased diameter portion and a decreased diameter portion defined in a circumferential surface thereof. The stator core is lightly press fitted to the increased diameter portion. In addition, an adhesive is arranged in a gap between the decreased diameter portion and an inner circumferential surface of the stator core.
As illustrated in FIG. 1(B) of JP-A 8-228465, an upper portion of the stator core is fixed to the frame through the adhesive. The upper portion of the stator core is fixed to the frame with lower strength than a lower portion of the stator core, which is slightly press fitted thereto. Thus, an exciting force due to a driving torque may cause a deformation of the stator core, which may cause a vibration of the spindle motor.